Equipments under Control (EUC) are facilities, equipment, plants or even devices or apparatuses that are used in production, logistics, medicine or other areas of application and can cause hazards.
EUC devices must be protected by safety-related systems
.EUC systems are covered in Part 4 of the IEC 61508 basic safety standards for functional safety. There they are described as "part of the overall safety, related to the EUC and the EUC control system, which depends on the correct functioning of the safety-related E/E/PE system
and other risk-reducing measures". Safety measures are required if the EUC system causes hazards to an unacceptable degree.